Porous bodies and method of production thereof

ABSTRACT

The invention provides a method for preparing water dispersible or water soluble porous bodies and the bodies themselves The bodies have an intrusion volume as measured by mercury porosimetry of at least about 3 ml/g and comprise a three dimensional open-cell lattice containing less than 10% by weight of a water soluble polymeric material and 5 to 90% by weight of a surfactant, with the proviso that said porous bodies are not spherical beads having an average bead diameter of 0.2 to 5 mm. The method comprises the steps of: a) providing an intimate mixture of the polymeric material and the surfactant in a liquid medium b) providing a fluid freezing medium at a temperature effective for rapidly freezing the liquid medium; c) cooling the liquid medium with the fluid freezing medium at a temperature below the freezing point of the liquid medium for a period effective to rapidly freeze the liquid medium; and d) freeze-drying the frozen liquid medium to form the porous bodies by removal of the liquid medium by sublimation.

TECHNICAL FIELD

The present invention relates to water soluble or dispersible porousbodies and to methods of producing such porous bodies.

BACKGROUND TO THE INVENTION

Certain surfactants, including, for example, the >C8 primary alkylsulphate (‘PAS’) surfactants having utility in detergent compositions,are difficult to dissolve in water at low temperatures. This may be dueto the surfactant forming a viscous phase on contact with water and thisphase can act as a mixing barrier, hindering further dissolution ofsurfactant. It may also be that the crystalline form of surfactant isvery stable at low temperatures. While it would be advantageous, forenvironmental reasons, to be able to use PAS and certain othersurfactants for laundering, and even more advantageous if this could bedone at low temperatures, the dissolution kinetics of PAS have precludedits widespread use in low temperature washing.

Our co-pending international patent application PCT/GB03/03226 describesthe formation of porous beads comprising a three dimensional open-celllattice of a water-soluble polymeric material with an average beaddiameter in the range 0.2 to 5 mm. These are typically ‘templated’materials formed by the removal of a non-aqueous dispersed phase from ahigh internal phase emulsion. The beads are freeze-dried to remove thebulk of the aqueous phase. This leaves a ‘skeletal’ form of the emulsionbehind. The beads dissolve rapidly in water and have the remarkableproperty that a water insoluble component dispersed in the emulsionprior to drying can also be dispersed in water on solution of the beads.Surfactant is present as an emulsifier.

BRIEF DESCRIPTION OF THE INVENTION

We have now determined that effectively polymer-free systems, i.e. whichcomprise a surfactant but little or no polymer can provide highly porousbodies which disperse rapidly on contact with water, even at lowtemperatures.

In accordance with a first aspect of the invention, there is providedwater dispersible or water soluble porous bodies comprising a threedimensional open-cell lattice containing:

-   (a) less than 10% by weight of water-soluble polymeric material    other than a surfactant, and-   (b) 5 to 95% by weight of a surfactant, said porous bodies having an    intrusion volume as measured by mercury porosimetry (as hereinafter    described) of at least about 3 ml/g

These porous bodies are particularly advantageous especially when theycontain a relatively high level of surfactant as this promotes rapiddissolution of the surfactant and dispersion of any optional waterinsoluble material for which the surfactant is a carrier.

The present invention also provides a method for the preparation of saidporous bodies which comprises the steps of:

-   (I) cooling an emulsion of:    -   a) An aqueous phase comprising the surfactant, and,    -   b) An immiscible second phase, to a temperature at which the        continuous phase becomes solid, and-   (II) subsequently removing the bulk of the continuous and dispersed    phases.

The cooled emulsion retains its structure when the bulk of the phasesare removed (preferably by freeze drying) leaving a solid,surfactant-containing lattice. This lattice retains its structureprovided that the ambient temperature does not rise above its meltingpoint. The lattice so produced is characterised by a large surface area,which greatly assists the solution of its components. This improvedsolution rate is particularly beneficial when the surfactant is beingused for delicate cleaning tasks such as for cleaning delicate fabricsor where only cold water is available for use in the cleaning process.

DETAILED DESCRIPTION OF THE INVENTION

In order that the present invention may be better understood and carriedforth into practice, it is described below with reference to variouspreferred features and particular embodiments.

Surfactant:

It is preferred that a substantial part of the structuring of thebodies, i.e. the lattice, is provided by the surfactant. Consequently,the surfactant is preferably a solid per-se at temperatures encounteredduring product storage, i.e. at temperature below 30 Celsius, preferablyat temperatures below 40 Celcius. In the alternative, the surfactant mayform a solid over an appropriate temperature range in the presence ofother materials present in the composition, such as builder salts.

The surfactant may be non-ionic, anionic, cationic, or zwitterionic.

Examples of suitable non-ionic surfactants include ethoxylatedtriglycerides; fatty alcohol ethoxylates; alkylphenol ethoxylates; fattyacid ethoxylates; fatty amide ethoxylates; fatty amine ethoxylates;sorbitan alkanoates; ethylated sorbitan alkanoates; alkyl ethoxylates;Pluronics™; alkyl polyglucosides; stearol ethoxylates; alkylpolyglycosides.

Examples of suitable anionic surfactants include alkylether sulfates;alkylether carboxylates; alkylbenzene sulfonates; alkylether phosphates;dialkyl sulfosuccinates; alkyl sulfonates; soaps; alkyl sulfates; alkylcarboxylates; alkyl phosphates; paraffin sulfonates; secondary n-alkanesulfonates; alpha-olefin sulfonates; isethionate sulfonates.

Examples of suitable cationic surfactants include fatty amine salts;fatty diamine salts; quaternary ammonium compounds; phosphoniumsurfactants; sulfonium surfactants; sulfonxonium surfactants.

Examples of suitable zwitterionic surfactants include N-alkylderivatives of amino acids (such as glycine, betaine, aminopropionicacid); imidazoline surfactants; amine oxides; amidobetaines. Mixtures ofsurfactants may be used.

The preferred surfactants are primary and secondary alcohol sulphatescontaining greater than C8 chain length, more preferably, the materialsknown commercially as ‘cocoPAS’.

Product Form:

The bulk density of the porous bodies is preferably in the range of fromabout 0.01 to about 0.2 g/cm³ more preferably from about 0.02 to about0.09 g/cm³, and most preferably from about 0.03 to about 0.08 g/cm³.

The intrusion volume of the porous bodies as measured by mercuryporosimetry (as hereinafter described) is at least about 3 ml/g, morepreferably at least about 4 ml/g, even more preferably at least about 5ml/g, and most preferably at least about 6 ml/g. For example, theintrusion volume may be from about 3 ml/g to about 30 ml/g, preferablyfrom about 4 ml/g to about 25 ml/g, more preferably from about 10 ml/gto about 20 ml/g.

Intrusion volume provides a very good measure (in materials of thisgeneral type) of the total pore volume within the porous bodies of thepresent invention.

The porous bodies may be in the form of powders, beads or mouldedbodies. Powders may be prepared by the disintegration of porous bodiesin the form of beads or disintegration of bodies during other stages ofthe production process.

Porous Bodies as Carriers:

The porous bodies of the present invention optionally include within thelattice hydrophobic materials to be dispersed when the bodies aredispersed in an aqueous medium. Dispersion into an aqueous medium ofsuch hydrophobic materials is much improved.

The hydrophobic materials may be incorporated into the lattice bydissolving them in the discontinuous oil phase of an oil-in-wateremulsion from which the lattice is made.

The present invention also includes, in a further aspect, solutions ordispersions comprising surfactant and a hydrophobic material formed byexposing to an aqueous medium porous bodies according to the presentinvention, wherein said bodies comprise the hydrophobic material.

There are many instances in personal care products such as deodorants,skin and hair cleaning or care products or in household products such aslaundry cleaning and care products or household cleaning or careproducts for hard and soft surfaces where it is desirable to administerhydrophobic materials in an aqueous environment. Because of thehydrophobic nature of these materials they are often reluctant todisperse in an aqueous environment. The use of the porous bodies of thepresent invention facilitates this dispersion and in many cases enableshydrophobic materials to be dispersed more effectively than previously.

It may be required to disperse the hydrophobic materials at the pointwhere the product is being used. In this case the porous bodies of thepresent invention will be contained in the product until it is used byexposing it to an aqueous environment, at which time thewater-soluble/dispersible lattice of the porous body will break downreleasing the hydrophobic material.

The porous bodies of the present invention may be used to introducehydrophobic materials into products, for example, liquid products duringthe manufacture of the products. In this case the lattice of the porousbodies of the present invention will break down when the porous bodiescontact an aqueous environment during manufacture releasing thehydrophobic material in a form in which it can be more readilyincorporated into the product being manufactured.

The porous bodies of the present invention may be used to transportmaterials to sites where they can be incorporated into products. Byconverting liquid products into porous bodies the need to transportlarge amounts of liquids can be avoided resulting in significant costsavings and safer transport of materials which are potentially hazardouswhen transported in a liquid form. Materials which would be potentiallyunstable if stored or transported in liquid form may be incorporatedinto the porous bodies of the present invention and stored ortransported with less risk of degradation.

The incorporation of potentially unstable hydrophobic materials, forexample vaccines, vitamins or perfumes, into the porous bodies of thepresent invention may protect them from degradation during storage priorto use.

Some specific examples of products in which the porous bodies of thepresent invention may be used are given below. These are given asexamples only and are not intended to limit the applicability of thepresent invention. Those skilled in the art will however realise thatthe porous bodies of the present invention will have utility in otherareas not specifically exemplified herein.

Hydrophobic materials that are released from the porous bodies of thepresent invention at the time of use may include: —

-   -   antimicrobial agents, for example: triclosan, climbazole,        octapyrox, ketoconizole, phthalimoperoxyhexanoic acid (PAP),        quaternary ammonium compounds, colloidal silver, zinc oxide.    -   antidandruff agent for example: zinc pyrithione    -   skin lightening agents for example 4-ethylresorcinol    -   fluorescing agents for example: 2,5-bis(2-benzoxazolyl)thiophene        for use on fabrics (such as cotton, nylon, polycotton or        polyester) in laundry products    -   skin conditioning agents, for example cholesterol    -   antifoaming agents for example isoparrafin    -   hair conditioning agents for example quaternary ammonium        compounds, protein hydrolysates, peptides, ceramides and        hydrophobic conditioning oils for example hydrocarbon oils such        as paraffin oils and/or mineral oils, fatty esters such as        mono-, di-, and triglycerides, silicone oils such as        polydimethylsiloxanes (e.g. dimethicone) and mixtures thereof    -   fabric conditioning agents for example quaternary ammonium        compounds having 1 to 3, preferably 2 optionally substituted        (C8-C24) alk(en)yl chains attached to the nitrogen atom by one        or more ester groups; hydrophobic monoparticles such as a        sucrose polyester for example sucrose tetra-tallowate; silicones        for example polydimethylsiloxane    -   thickening agents for example hydrophobically modified cellulose        ethers such as modified hydroxyethylcelluloses    -   dyes for example dyes intended to change the colour of fabrics,        fibres, skin or hair.    -   UV protecting agents such as sunscreens for example octyl        methoxycinnamate (Parsol MCX), butyl methoxydibenzoylmethane        (Parsol 1789) and benzophenone-3 (Uvinul M-40), ferulic acid.    -   bleach or bleach precursors for example        6-N-phthalimidoperoxyhexanoic acid (PAP) or photobleaching        compounds. Dispersing the bleach from the porous bodies of the        present invention results in the bleach being more finely        dispersed and reduces the spot damage seen when larger particles        of the bleach contact a fabric    -   antioxidants for example hydrophobic vitamins such as vitamin E,        retinol, antioxiants based on hydroxytoluene such as Irganox or        commercially available antioxidants such as the Trollox series.    -   insecticides, pesticides, herbicides that are stored as solid        compositions before use but which are made up into liquid for        spraying onto animals or crops    -   perfumes or flavourings or precursors thereto    -   pharmaceutically or veterinary active materials. There is a need        for pharmaceutical compositions which can be taken by the        consumer without the need to ingest the composition with a drink        such as water. These compositions interact with the moisture in        the oral cavity to release the active ingredient which is then        ingested by the consumer. By incorporating the pharmaceutically        or veterinary active molecule in the porous bodies of the        present invention, pharmaceutical compositions which meet this        need can be prepared.    -   In a similar way to that described above pharmaceutical and        veterinary active ingredients may be formulated so that they        release the active material into the nasal, occular, pulmonary        or rectal cavities or on the skin where they may act topically        or they may be absorbed transdermally to act systemically    -   By using the appropriate polymeric material in the lattice of        the porous bodies of the present invention, porous bodies can be        made that remain intact until the conditions (for example        temperature or pH) change to those under which dispersion can        occur. Thus dispersion can be delayed until a certain        temperature has been reached or until the pH has changed to a        suitable value such as would occur as the porous bodies pass        down the GI tract. The acidity in the GI tract reduces down the        GI tract and porous bodies which disperse hydrophobic actives        only when the porous bodies are exposed to higher pH conditions        enable pharmaceutically or veterinary active materials to be        released only in the intestine having passed through the stomach        intact.

Examples of situations where the porous bodies of the present inventionare used to incorporate a hydrophobic material into a product during themanufacture of that product include: —

-   -   the introduction of hydrophobic materials such as fluorescers;        enzymes; bleaches; hydrophobic polymers for example        hydrophobically modified polyacrylates, silicones,        hydrophobically modified polyvinylpyrrolidone, sulpha alkyl        polysaccharides, Jaguar and JR polymers; fatty alcohols or        acids; dyes for example shading dyes or black dyes for colour        recovery into laundry products.    -   the use of porous bodies according to the present invention        containing hydrophobic dyes in the manufacture of water soluble        inkjet compositions.    -   the introduction of porous bodies containing different        hydrophobic materials enables a manufacturer to produce a single        base formulation into which the desired hydrophobic materials        may be introduced by the use of the appropriate porous body of        the present invention.    -   the use of porous bodies containing hydrophobic polymers which        disperse into water as the lattice breaks down to form a latex.        The use of such latexes containing appropriate hydrophobic        polymers deposited onto fabric imparts crease resistance or        easy-iron properties to the fabric.

The porous bodies of the present invention may include within thelattice, water soluble materials which will be dispersed when the bodiesare dispersed in an aqueous medium. The water soluble materials may beincorporated into the lattice by dissolving them in the liquid mediumfrom which they are made.

Examples of suitable water soluble materials include:—

-   -   Water soluble vitamins such as vitamin C;    -   water soluble fluorescers such as the        4,4′-bis(sulfo-styryl)biphenyl disodium salt (sold under the        trade name Tinopal CBS-X;    -   activated aluminium chlorohydrate;    -   transition metal complexes used as bleaching catalysts;    -   water soluble polymers such as polyesters isophthalic acid),        gerol, xanthan gum, or polyacrylates;        diethylenetriaminepentaacetic acid (DTPA);        or mixtures thereof.

The porous bodies of the present invention may include within thelattice, materials which will be dispersed as very small particles whenthe polymeric bodies are dispersed in an aqueous medium. These materialsmay be incorporated into the lattice by dissolving or dispersing them inthe liquid medium from which the porous bodies are made. If theparticles are less than 1 micron, preferably less than 0.5 micron andthey are incorporated into skincare products then the particles will notbe felt by the user as the dispersed porous bodies are applied to theskin.

Water Soluble Polymers:

Preferably the porous bodies of the present invention contain less than5% wt more preferably less than 3% by weight of water-soluble polymericmaterial.

When present, the polymeric material is a material that would beconsidered as “water soluble” by those skilled in the art i.e. if itforms a homogeneous solution in water. Water soluble polymers generallypossess pendant polar or ionizable groups (e.g. —C═O, —OH, —N(R₁)(R₂) inwhich R₁ and R₂, which may be the same or different, are independently Hor (C1 to C4)alkyl, —N(R₃)(R₄)(R₅)⁺ in which R₃, R₄ and R₅ which may bethe same or different, are independently H or (C1 to C4)alkyl,—CON(R₆)(R₇) in which R₆ and R₇, which may be the same or different, areH or (C1 to C4) alkyl, —CH₂CH₂O—, —CO₂H or salts thereof, —SO₃H or saltsthereof groups) on a backbone chain which may be hydrophobic.

If water-soluble polymeric materials are incorporated into the porousbodies of the present invention, the time taken for the bodies todissolve or disperse may be significantly reduced. For detergentapplications, the nature of the lattice should be such that thedissolution or dispersion of the bodies preferably occurs in less thanthree minutes, more preferably less than two minutes, most preferablyless than one minute.

Examples of water soluble polymeric materials include: —

-   (a) natural polymers (for example naturally occurring gums such as    guar gum or locust bean gum or a polysaccharide such as dextran or    cellulose;-   (b) cellulose derivatives for example xanthan gum, xyloglucan,    cellulose acetate, methylcellulose, methyethylcellulose,    hydroxyethylcellulose, hydroxyethylmethylcellulose,    hydroxy-propylcellulose, hydroxypropylmethylcellulose (HPMC),    hydroxy-propylbutylcellulose, ethylhydroxyethylcellulose,    carboxy-methylcellulose and its salts (eg the sodium salt—SCMC), or    carboxymethylhydroxyethylcellulose and its salts (for example the    sodium salt);-   (c) homopolymers of any one of the monomers listed in Table 1 below;-   d) copolymers prepared from two or more monomers listed in Table 1    below;-   (e) mixtures thereof

TABLE 1 vinyl alcohol, acrylic acid, methacrylic acid acrylamide,methacrylamide acrylamide methylpropane sulphonates aminoalkylacrylatesaminoalkylmethacrylates hydroxyethylacrylate hydroxyethylmethylacrylatevinyl pyrrolidone vinyl imidazole vinyl amines vinyl pyridineethyleneglycol ethylene oxide ethyleneimine styrenesulphonatesethyleneglycolacrylates ethyleneglycol methacrylate

When the polymeric material is a copolymer it may be a statisticalcopolymer (heretofore also known as a random copolymer), a blockcopolymer, a graft copolymer or a hyperbranched copolymer. Comonomersother than those listed in Table 1 may also be included in addition tothose listed if their presence does not destroy the water soluble orwater dispersible nature of the resulting polymeric material.

Examples of suitable homopolymers include polyvinylalcohol, polyacrylicacid, polymethacrylic acid, polyacrylamides (such aspoly-N-isopropylacrylamide), polymethacrylamide; polyacrylamines,polymethylacrylamines, (such as polydimethylaminoethyl-methacrylate andpoly-N-morpholinoethylmethacrylate, polyvinyl-pyrrolidone,polyvinylimidazole, polyvinylpyridine, polyethylene-imine andethoxylated derivatives thereof.

Method of Preparation:

As noted above, one method suitable for preparing the porous bodiescomprises the steps of: cooling a surfactant-containing oil-and-wateremulsion to a temperature at which the continuous phase becomes solid,and subsequently removing the bulk of the continuous and dispersedphases.

Accordingly a further aspect of the present invention, there is provideda method the preparation of water dispersible or water soluble porousbodies comprising a three dimensional open-cell lattice containing:

-   (a) less than 10% by weight of a water soluble polymeric material    and-   (b) 5 to 90% by weight of a surfactant,    said porous bodies having an intrusion volume as measured by mercury    porosimetry (as herein described) of at least about 3 ml/g with the    proviso that said porous body is not a spherical bead having an    average bead diameter of 0.2 to 5 mm comprising the steps of:-   a) providing an intimate mixture of the surfactant in a liquid    medium-   b) providing a fluid freezing medium at a temperature effective for    rapidly freezing the liquid medium;-   c) cooling the liquid medium with the fluid freezing medium at a    temperature below the freezing point of the liquid medium for a    period effective to rapidly freeze the liquid medium; and-   (d) freeze-drying the frozen liquid medium to form the bodies by    removal of the liquid medium by sublimation.

The intimate mixture of the surfactant in the liquid medium may be anoil-in-water emulsion comprising a continuous aqueous phase containingthe polymeric material, a discontinuous oil phase and the surfactant.

When the porous body is to be in the form of a powder the cooling of theliquid medium may be accomplished by spraying the liquid medium inatomised form into the fluid freezing medium.

When the porous body is to be in the form of beads the cooling of theliquid medium may be accomplished by dropping drops of the liquid mediuminto the fluid freezing medium.

Porous bodies in the form of moulded bodies may be made by pouring theliquid medium into a mould and cooling the liquid medium by the fluidfreezing medium. In a preferred process of the invention to make mouldedbodies, the liquid medium is poured into a pre-cooled mould surroundedby fluid freezing medium.

The frozen liquid medium may be freeze-dried by exposing the frozenliquid medium to high vacuum. The conditions to be used will be wellknown to those skilled in the art and the vacuum to be applied and thetime taken should be such that all the frozen liquid medium present hasbeen removed by sublimation.

In the case of moulded porous bodies freeze-drying may take place withthe frozen liquid medium still in the mould. Alternatively, the frozenliquid medium may be removed from the mould and subsequentlyfreeze-dried.

The freeze-drying step may be performed for up to around 72 hours inorder to obtain the porous bodies of the present invention.

The above process preferably uses an oil-in-water emulsion comprising acontinuous aqueous phase and a discontinuous oil phase. The surfactantusefully acts as an emulsifier for the emulsion.

Surfactants suitable for use as emulsifiers in oil-in-water emulsionspreferably have an HLB value in the range 8 to 18. It is preferred thatthe surfactant is present in the liquid medium in a concentration ofabout 1% to about 60% by weight. More preferably, the surfactant ispresent in the liquid medium in a concentration of about 2% to about 40%by weight and a yet more preferred concentration is about 5% to about25% by weight.

The discontinuous oil phase of the oil-in-water emulsion preferablycomprises a material which is immiscible with the continuous phase,which freezes at a temperature above the temperature which is effectivefor rapidly freezing the aqueous medium and which is removable bysublimation during the freeze drying stage.

The discontinuous oil phase of the emulsion may be selected from one ormore from the following group of organic solvents:

-   -   alkanes, such as heptane, n-hexane, isooctane, dodecane, decane;    -   cyclic hydrocarbons, such as toluene, xylene, cyclohexane;    -   halogenated alkanes, such as dichloromethane, dichoroethane,        trichloromethane (chloroform), fluorotrichloromethane and        tetrachloroethane;    -   esters such as ethyl acetate;    -   ketones such as 2-butanone;    -   ethers such as diethyl ether;    -   volatile cyclic silicones such as cyclomethicone;        and mixtures thereof.

Preferably, the organic solvent comprises from about 10% to about 95%v/v of the emulsion, more preferably from about 20% to about 60% v/v. Apreferred solvent is cyclohexane as the freezing point of cyclohexane ishigher than that of water and the specific heat capacity for cyclohexaneis much lower than that of water. This induces rapid freezing of theemulsion.

Preferably, the fluid medium is at a temperature below the freezingpoint of all of the components and is preferably at a much lowertemperature to facilitate rapid freezing. The fluid freezing medium ispreferably a liquified substance which is a gas or vapour at standardtemperature and pressure. The liquified fluid freezing medium may be atits boiling point during the freezing of the liquid medium or it may becooled to below its boiling point by external cooling means. The fluidfreezing medium may be selected from one or more of the following group;liquid air, liquid nitrogen (b.p. −196° C.), liquid ammonia (b.p. −33°C.), liquified noble gas such as argon, liquefied halogenatedhydrocarbon such as trichloroethylene, chlorofluorocarbons such asFreon®, hexane, dimethylbutene, isoheptane or cumene. Mixtures oforganic liquids and solid carbon dioxide may also be used as the fluidfreezing medium. Examples of suitable mixtures include chloroform oracetone and solid carbon dioxide (−77° C. and diethyl ether and solidcarbon dioxide (−100° C.).

The fluid medium is removed during freeze drying, preferably undervacuum and is preferably captured for reuse. Due to the very low boilingtemperature, inertness, ease of expulsion and economy, liquid nitrogenis the preferred fluid freezing medium.

The emulsions are typically prepared under conditions which are wellknown to those skilled in the art, for example, by using a magneticstirring bar, a homogenizer, or a rotator mechanical stirrer.

The porous polymeric bodies produced usually comprise of two types ofpores. One is from the sublimation of solid ice. The other kind of porestructure results from the sublimation of the oil phase.

The method for producing porous bodies according to the presentinvention, will now be more particularly described, by way of exampleonly, with reference to the accompanying Examples.

EXAMPLES

In the Examples that follow the dissolution time is measured as using aweighed sample of the polymeric bodies, which was stirred gently withwater until the stirred mixture was clear to the eye. The time at whichthe mixture became clear to the eye was recorded as the dissolutiontime.

The freeze-drier used was an Edwards Supermodulyo. This was operatedwith an average vacuum of 0.2 mbar and at −50° C.

Example 1 Hydrophilic Surfactant

1 g of sodium dodecyl sulfate (SDS) was dissolved in 5 ml of water. Tothis aqueous solution was added 0.5 mg of oil red in 5 ml cyclohexanewith vigorous stirring (using a RW11 Basic IKA paddle stirrer). Theemulsion formed was sprayed into liquid nitrogen using a trigger sprayand the resulting frozen powder was freeze-dried to form a powder. Thepowder was highly porous, rapidly dissolving and dispersed thehydrophobic dye quickly into water to form a clear red ‘solution’

Example 2 Hydrophobic Surfactant

An experiment was conducted in order to produce highly porous, rapidlydissolving oil-soluble powders that disperse a hydrophilic dye quicklyinto oil.

0.2 g of sodium dioctyl sulfosuccinate was dissolved in 4 ml of toluene.To this organic solution was added 0.01 g of direct yellow 50 in 4 ml ofwater with vigorous stirring (as described in the previous example). Theemulsion formed was sprayed into liquid nitrogen using a trigger sprayand the resulting frozen powder was freeze-dried to form a powder. Thispowder dissolved readily into acetone to form a clear ‘yellow’ solution.

Example 3 Dissolution of cocoPAS

A 12.5% wt aqueous solution of sodium lauryl sulfate (cocoPAS, EMAL10PHD, ex Kao) was prepared by adding cocoPAS to deionised water. Asample of the solution (4 ml) was stirred with a type RW11 Basic IKApaddle stirrer and cyclohexane (6 ml) was added to form an emulsionhaving 75% v/v of discontinuous phase.

The beaker containing the emulsion was frozen in liquid nitrogen.

Once frozen, the emulsion was placed in a freeze-drier overnight. Thesame solution was made into beads by dripping the emulsion into liquidnitrogen, or made into a powder by spraying the emulsion into liquidnitrogen. Once frozen, the emulsion was placed in a freeze-drierovernight as before.

10 mg of beads (or monolith, or powder) were added to 2 ml water, andstirred at 250 rpm. Using a stopwatch, the time to form a clear solutionwas determined. Results are given in the table below:

TABLE 2 Dissolution of CocoPAS Dissolution at 5 Dissolution at 20Material ° C. ° C. Na cocoPAS >2 min - not fully  1 min as receiveddissolved Monolith  2 min 10 sec 30 sec Beads  2 min 20 sec Powder 35sec 30 sec

It can be seen that the dissolution time of the cocoPAS wassignificantly improved by forming it into the porous bodies of thepresent invention.

Example 4 CocoPAS Plus Fluorescer

9 g of CocoPAS (sodium lauryl sulphate, EMAL 10PHD, ex Kao) wasdissolved in 120 ml of water. To this aqueous solution was added 11.0 gof Tinopal™ SOP in 120 ml of dichloromethane with vigorous stirring. Theemulsion formed was sprayed into liquid nitrogen using a trigger sprayand the resulting frozen powder was freeze-dried to form a powder.

A sample was also made containing 30% wt loading of the fluorescer, i.e.1 g Tinopal and 2.3 g of cocoPAS with 40 ml water and 40 mldichloromethane.

Both samples dissolved quickly into water to give clear ‘solutions’.

Example 5 CocoPAS Plus Fluorescer in Products

Samples of the 10% and 30% loaded bodies, prepared as disclosed inExample 4 were added to Brilhante (ex Gessy Lever, 2004) baseformulation, without any fluorescer present. This was done inproprortions to give final products with 0.05, 0.1 and 0.2% wt in thefinal formulation. The change in Ganz whiteness (Delta G) on clothmonitors, before and after washing, was compared with that obtained withtwo control formulations:

-   a) Brilhante base with the addition of 0.1 wt % fluorescer on    product, added by dissolution into ethanol—the ‘ideal situation’.-   b) Brilhante base with the addition of 0.1 wt % fluorescer on    product, dispersed in nonionic surfactant.

Measurements were performed for cotton, nylon and polyester. Results areshown in table 3 below:

TABLE 3 % wt on Delta G Delta G Delta G Ex. Loading prod. carrier CottonNylon Polyester Con. — 0.1 Ethanol 21.94 38.15 8.88 1 Con. — 0.1Nonionic 2.95 8.89 1.74 2 5a 10% 0.05 CocoPAS 18.34 26.08 6.90 5b 10%0.1 CocoPAS 21.68 33.35 9.11 5c 10% 0.2 CocoPAS 27.09 36.59 10.47 5d 30%0.05 CocoPAS 12.86 22.27 6.83 5e 30% 0.1 CocoPAS 19.69 30.34 8.97 5f 30%0.2 CocoPAS 24.99 36.02 10.46

From the table it can be seen that the method of the invention givesdeposition of fluorescer which is comparable with dosage of fluorescerin ethanol.

1. Water-soluble porous bodies comprising a three dimensional,oil-in-water emulsion-templated, freeze-dried, open-cell lattice, fromwhich the bulk of the water and oil have been removed comprising: (a)less than 10% by weight of water-soluble polymeric material other than asurfactant, said water-soluble polymeric material forming a homogeneoussolution in water; (b) about 5 to 95% by weight of a surfactant; and,(c) a water-insoluble material incorporated into said lattice to bedispersed when the water-soluble porous body dissolves; said porousbodies having an intrusion volume as measured by mercury porosimetry ofat least about 3 ml/g, and comprise two types of pores: one from thesublimation of solid ice of the continuous aqueous phase and one fromthe sublimation of the solid oil of the discontinuous phase; whereinsaid porous bodies are powders having a particle size below about 0.2 mmor moulded bodies having a particle size above about 5 mm; with theproviso that said porous bodies are not spherical beads having anaverage bead diameter of 0.2-5.0 mm; wherein said water-solublepolymeric material is a water-soluble natural gum, a water-solublepolysaccharide, a water-soluble cellulose derivative or a water-solublehomopolymer or copolymer comprising (co)monomers selected from the groupconsisting of: vinyl alcohol, acrylic acid, methacrylic acid acrylamide,methacrylamide acrylamide methylpropane sulphonates aminoalkylacrylatesaminoalkylmethacrylates hydroxyethylacrylate hydroxyethylmethylacrylatevinyl pyrrolidone vinyl imidazole vinyl amines vinyl pyridineethyleneglycol ethylene oxide ethyleneimine styrenesulphonatesethyleneglycolacrylates ethyleneglycol methacrylate; and mixturesthereof.
 2. A method of preparing water-soluble porous bodies comprisinga three dimensional, oil-in-water emulsion-templated, freeze-driedopen-cell lattice comprising: (a) less than about 10% by weight of awater-soluble polymeric material other than a surfactant; saidwater-insoluble polymeric material forming a homogeneous solution inwater; (b) about 5 to 90% by weight of a surfactant, and (c) awater-insoluble material incorporated into said lattice to be dispersedwhen the water-soluble porous body dissolves; said porous bodies havingan intrusion volume as measured by mercury porosimetry of at least about3 ml/g; wherein said porous bodies are powders having a particle sizebelow about 0.2 mm or moulded bodies having a particle size above 5 mm;and with the proviso that said porous bodies are not spherical beadshaving an average bead diameter of about 0.2-5.0 mm; comprising thesuccessive steps of: a) providing an oil-in-water emulsion comprisingthe water-soluble polymeric material, the water-insoluble material in adiscontinuous oil phase and the surfactant, wherein the aqueous phaseand the oil phase together form a liquid medium, and the discontinuousphase of the emulsion comprises about 10 to about 95% by volume of theemulsion; b) providing a fluid freezing medium at a temperatureeffective for rapidly freezing the liquid medium; c) cooling the liquidmedium with the fluid freezing medium at a temperature below thefreezing point of the liquid medium for a period effective to rapidlyfreeze the liquid medium; and d) freeze-drying the frozen liquid mediumto form the porous bodies by removal of the bulk of the liquid medium bysublimation, such that said porous bodies comprise two types of pores:one from the sublimation of solid ice and one from the sublimation ofthe solid oil of the discontinuous oil phase.
 3. Porous bodies asclaimed in claim 1, wherein the water-soluble cellulose derivative isselected from the group consisting of xanthan gum, xyloglucan, celluloseacetate, methylcellulose, methyethylcellulose, hydroxyethyl-cellulose,hydroxyethylmethylcellulose, hydroxyl-propylcellulose,hydroxypropylmethylcellulose (HPMC), hydroxypropylbutylcellulose,ethylhydroxyethylcellulose, carboxymethylcellulose and its salts, orcarboxymethyl-hydroxyethylcellulose and its salts.
 4. Porous bodies asclaimed in claim 1 wherein the surfactant is non-ionic, anionic,cationic, or zwitterionic.
 5. Porous bodies as claimed in claim 1wherein the surfactant is solid at ambient temperature.
 6. Porous bodiesas claimed in claim 1 wherein the surfactant is selected from the groupconsisting of ethoxylated triglycerides; fatty alcohol ethoxylates;alkylphenol ethoxylates; fatty acid ethoxylates; fatty amideethoxylates; fatty amine ethoxylates; sorbitan alkanoates; ethylatedsorbitan alkanoates; alkyl ethoxylates; pluronics; alkyl polyglucosides;stearol ethoxylates; alkyl polyglycosides; alkylether sulfates;alkylether carboxylates; alkylbenzene sulfonates; alkylether phosphates;dialkyl sulfosuccinates; alkyl sulfonates; soaps; alkyl sulfates; alkylcarboxylates; alkyl phosphates; paraffin sulfonates; secondary n-alkanesulfonates; alpha-olefin sulfonates; isethionate sulfonates; fatty aminesalts; fatty diamine salts; quaternary ammonium compounds; phosphoniumsurfactants; sulfonium surfactants; sulfonxonium surfactants; N-alkylderivatives of amino acids; imidazoline surfactants; amine oxides;amidobetaines; and mixtures thereof.
 7. Porous bodies as claimed inclaim 1 wherein the porous polymeric bodies have water-soluble materialincorporated into the polymeric lattice; wherein the water solublematerial is selected from the group consisting of water solublevitamins; water soluble fluorescers; activated aluminium chlorohydrate;transition metal complexes used as bleaching catalysts; water solublepolymers; diethylenetriaminepentaacetic acid (DTPA); primary andsecondary alcohol sulphates containing greater than C8 chain length; ormixtures thereof.
 8. Water soluble porous polymeric bodies as claimed inclaim 1 wherein the water-insoluble material is selected from the groupconsisting of antimicrobial agents; antidandruff agent; skin lighteningagents; fluorescing agents; antifoams; hair conditioning agents; fabricconditioning agents; skin conditioning agents; dyes; UV protectingagents; bleach or bleach precursors; antioxidants; insecticides;pesticides; herbicides; perfumes or precursors thereto; flavourings orprecursors thereto; pharmaceutically active materials; hydrophobicpolymeric materials; and mixtures thereof.
 9. A method as claimed inclaim 2 wherein the cooling of the liquid medium is accomplished byspraying an atomised emulsion into the fluid freezing medium; bydropping drops of the emulsion into the fluid freezing medium or bypouring the emulsion into a mould and cooling the emulsion in the mould.10. A method as claimed in claim 2 wherein the water-soluble polymericmaterial is a water-soluble natural gum, a water-soluble polysaccharide,a water-soluble cellulose derivative or a water-soluble homopolymer orcopolymer comprising (co)monomers selected from the group consisting of:vinyl alcohol, acrylic acid, methacrylic acid acrylamide, methacrylamideacrylamide methylpropane sulphonates aminoalkylacrylatesaminoalkylmethacrylates hydroxyethylacrylate hydroxyethylmethylacrylatevinyl pyrrolidone vinyl imidazole vinyl amines vinyl pyridineethyleneglycol ethylene oxide ethyleneimine styrenesulphonatesethyleneglycolacrylates ethyleneglycol methacrylate; and mixturesthereof.
 11. A method as claimed in claim 2 wherein the surfactant isnon-ionic, anionic, cationic, or zwitterionic.
 12. A method as claimedin claim 2 wherein the surfactant is solid at ambient temperature.
 13. Amethod as claimed in claim 2 wherein the surfactant has an HLB value of8 to
 18. 14. A method as claimed in claim 2 wherein the surfactant isselected from the group consisting of ethoxylated triglycerides; fattyalcohol ethoxylates; alkylphenol ethoxylates; fatty acid ethoxylates;fatty amide ethoxylates; fatty amine ethoxylates; sorbitan alkanoates;ethylated sorbitan alkanoates; alkyl ethoxylates; pluronics; alkylpolyglucosides; stearol ethoxylates; alkyl polyglycosides; alkylethersulfates; alkylether carboxylates; alkylbenzene sulfonates; alkyletherphosphates; dialkyl sulfosuccinates; alkyl sulfonates; soaps; alkylsulfates; alkyl carboxylates; alkyl phosphates; paraffin sulfonates;secondary n-alkane sulfonates; alpha-olefin sulfonates; isethionatesulfonates; fatty amine salts; fatty diamine salts; quaternary ammoniumcompounds; phosphonium surfactants; sulfonium surfactants; sulfonxoniumsurfactants; N-alkyl derivatives of amino acids (such as glycine,betaine, aminopropionic acid); imidazoline surfactants; amine oxides;amidobetaines; and mixtures thereof.
 15. A method as claimed in claim 2wherein the discontinuous phase of the emulsion comprises 20 to 60% byvolume of the emulsion.
 16. A method as claimed in claim 2 wherein thediscontinuous phase of the emulsion is selected from the groupconsisting of alkanes; cyclic hydrocarbons; halogenated alkanes; esters;ketones; ethers; volatile cyclic silicones and mixtures thereof. 17.Solutions or dispersions comprising water-soluble polymeric materialsand surfactant formed by exposing the water-soluble porous bodies ofclaim 2 to an aqueous medium.